The centers are arranged in three columns.
The left column is called the Pillar of Severity.

This represents the female side of man and contains three sephira:
Binah (Understanding), Geburah (Severity) and Hod (Splendor).

The right column is called the Pillar of Mercy.

This represents the male side of man and also contains three sephira:
Chokmah (Wisdom), Chesed (Mercy) and Netzach (Victory).

The middle pillar is called the Pillar of Equilibrium.
It represents the balance between the male and female pillars.
It contains four sephira:
Kether (Crown), Tiphareth (Beauty), Yesod (Foundation) and Malkuth (Kingdom).

The Kabbala requires four of these Trees, one for each world of the cosmos.

The Four Worlds:

Atziluth:
Representing the archetypal world, pure Divinity, and Yod of the Hebrew Name of God.
It corresponds to the Suit of Wands in the Tarot.

Briah:
Representing the creative world, the Archangelic, and thee in the Hebrew Name of God.
It corresponds to the Suit of Cups.

Yetzirah:
Represents the formative world, the Angelic, and Vau is the Hebrew name of God.
It corresponds to the Suit of Swords.

Assiah:
Representing the material world, man, and the final He in the Hebrew Name of God.
It corresponds to the Suit of Coins.

Sphere 1:
KETER ....CROWN, GOD, INFINITE LIGHT & WISDOM, TOTAL & SUPREME CONSCIOUSNESS

Sphere 2:
CHOHMAN ...MALE YANG ENERGIES, PURE ENERGY, SPIRITUAL FORCE, COSMIC FATHER

Sphere 3:
BINAH...YIN ENERGY, COMPASSION, PURE LOVE & UNDERSTANDING, THE COSMIC MOTHER

Sphere 4:
CHESED...THE RULER, MAJESTY, POWER & AUTHORITY, CONSOLIDATOR OF THINGS

Sphere 5:
GEBURAH...THE WARRIOR, SPSERER OF MARS, STRENGTH, JUSTICE, PHYSICAL POWER

Sphere 6:
TIPERETH...THE SUN, HARMONY, BEAUTY, PERFECTION, UNITY, CREATION

Sphere 7:
NEDZACH...THE LOVER, VENUS, ART, CREATIVITY INSPIRATION & EROTIC SPIRITUALITY

Sphere 8:
HOD...THE INTELLECT, MERCURY, COMMUNICATION

Sphere 9:
YESOD...THE MOON, VISION & DEEP MEMORY, THE CYCLES IN & AROUND US, ILLUSION

Sphere10:
MALKUTH... PHYSICAL REALITY, DEATH, PAIN, HEALING

Sphere11:
DAATH... THE ABYSS, RANDOM CHAOS OF THOUGHT & CONCEPTION